Lester Shubin, a former Justice Department researcher who first thought to use Kevlar in bullet-resistant vests, died after a heart attack at his Fairfax County home last week at the age of 84, reports the Washington Post.

Shubin was working for the National Institute for Justice, the research and development branch of the Justice Department, in the early 1970s when DuPont came out with what he called a “funny yellow fabric” intended to replace steel belting on high-speed tires.

“We folded it over a couple of times and shot at it. The bullets didn’t go through,” Shubin was quoted as saying in a Justice Department report on the National Institute for Justice’s accomplishments.

Shubin obtained $5 million in research money from the Justice Department as his fellow researcher began developing tests. Kevlar vests have been credited with saving the lives of more than 3,000 law enforcement officers since 1975.

In his capacity as a researcher, Shubin was one of the first to recommend that dogs be used to find bombs.

“We learned that basically any dog could find explosives or drugs, even very small dogs like Chihuahuas, whose size could be an advantage,” Shubin said. “Who is going to look twice at someone in a fur coat carrying a dog? But that dog could smell a bomb as well as a German shepherd.”

Shubin was born in Philadelphia on Sept. 27, 1925 and served in the Army in France and Germany. He was among the troops that liberated the Dachau concentration camp, his son, Harry Shubin, told the Washington Post.